Hi,
I have (5V, 5W) solar panel that has USB connection can directly plug into the electron, I tried it and I can see LiPo battery charging from the electron red LED however the battery still drop, so do I need more Watt?
Is that because of my data updated every 10 seconds?
your recommendation please.
Thank you very much
5V, 5W is just the max rating of that panel, if you have non-ideal conditions you’ll probably have less - especially at your latitude.
Also 5W @ 5V would only be 1A, with the Electron permanently running (especially if it’s a 2G version) most of that power will go into the device and very little will go into the LiPo.
So, for permanent usage you will definetly need a higher rated panel, especially when you also want to run through the night and in less sunny seasons.
Thank you
just to confirm, its working now but as you said higher rate will be better, i can see LiPo charging (very slow) because it is very sunny now.
Thanks again 
Also solar panels will only supply about 75% of their rated power output when under sun in the summer where the solar cells will be around 160 degrees F.
So 5w x 75% = 3.75w under perfect conditions.
Another thing to consider is how the 5v buck regulator that feeds the USB port from the varying solar panel output voltage reacts when the voltage drops out from a cloud. It may not recover very well, or it may work fine, you want good efficiency.
If you want high solar conversion efficiency consider something like this:
You will just need to set the solar voltage Max Power Voltage to the Vmp of the actual solar panel that your using so it operates at it’s max current output under all weather conditions.
Thank you RWB, and yes you are right, yesterday i wait the battery till get flat and then the electron can not recover using the solar panel, stayed off till i recharge the battery from outer source.